Sigma 24mm f1.8D EX DG Aspherical Macro lens for Nikon (F mount). Made for full 35mm frame. Autofocus is mechanical screw-drive type - if your camera doesn't have it - then use manual focus.  To engage autofocus - push focusing ring toward lens front, for manual focus - pull ring back. Glass is clean - no dust inside, no marks/scratches on coating. Both caps are included.